Fe3+掺杂对TiO2材料光催化活性的影响

采用溶胶-凝胶法制备了TiO2粉末,讨论了不同Fe3+掺杂浓度对TiO2光催化活性的影响,并采用XRD、UV-VIS检测技术对其进行了表征.结果表明,Fe3+掺杂能够显著的提高TiO2薄膜的光催化活性,最佳掺杂浓度为6.04×1016个·cm-3,且随着TiO2光催化活性的提高,薄膜的吸收带边发生了明显的红移,提高了可见光的利用率.XRD分析表明,Fe3+的掺杂使锐钛矿相TiO2的粒径明显减小,锐钛矿相含量明显增加.     

Gd3+掺杂纳米TiO2的制备及性能

采用溶胶-凝胶浸渍法制备了纯的和Gd3+掺杂的纳米TiO2,并利用XRD、UV-Vis漫反射光谱对样品进行了表征。考察了Gd3+掺杂对TiO2催化活性的影响。结果发现Gd3+的掺入阻止了TiO2由锐钛矿相向金红石相的转变,抑制了晶粒的生长。与纯TiO2相比,Gd3+掺杂的TiO2在紫外区的光吸收能力增强,TiO2催化剂光催化分解水制氢活性提高了56%。     

氧氮比对真空电弧沉积TiO_(2-x)N_x薄膜结构和性能的影响

采用真空电弧沉积技术在玻璃上制备了N掺杂TiO2复合薄膜。通过X射线电子能谱(XPS)、X射线衍射(XRD)、紫外可见光谱(UV-Vis)等测试技术研究了沉积过程中氧氮比对TiO2-xNx薄膜结构和性能的影响。实验结果表明,经500℃退火后的TiO2-xNx薄膜均为锐钛矿相,N原子在TiO2网络结构中以取代O原子的形式存在。TiO2-xNx复合薄膜在400～800 nm可见光区的透过率达60%,随着氮含量的增加,吸收边发生红移。在可见光下对酸性品红的降解表明TiO2-xNx薄膜具有可见光活性,随氧氮比的降低可见光催化活性逐渐增强。经自然光照射2 h,不同氧氮比制备的TiO2-xNx薄膜对大肠杆菌、金黄葡萄球菌的杀菌率均达99%以上。     

La掺杂对TiO2光催化剂的影响

采用溶胶-凝胶法制备了La掺杂的TiO2.通过X射线衍射分析、扫描电镜、紫外-可见光漫反射测试等手段对TiO2进行了结构和光吸收性能研究.结果表明La3+阻碍了锐钛矿向金红石转变,提高了晶形转变温度,La3+掺杂之后的TiO2粒径变小,La3+掺杂TiO2光吸收与煅烧温度有关.     

Cu-Ce/TiO_2的制备及其在室内甲醛气体中的光催化性能

利用环境测试舱模拟室内环境,通过设计正交实验,采用"极差分析"法对制备出的一系列的Cu-Ce/TiO2光催化效果进行分析。利用X射线衍射仪、扫描电镜仪和紫外-可见分光光谱仪,对微晶尺寸、晶相结构与光学性能进行分析。结果表明:Cu-Ce掺杂负载量、Cu-Ce摩尔比和烧结温度三因素对Cu-Ce/TiO2光催化效果影响的程度相互独立,即:Cu-Ce掺杂负载量Cu-Ce摩尔比烧结温度,当A3=3%、B3=1∶1和C2=500℃,得到优方案A3B3C2。掺杂Cu、Ce可以在TiO2晶体内形成锐钛型和金红石型的混晶结构,提高吸附能力,减少表面光生电子与光生空穴的复合,并且促进锐钛矿相向金红石相的转变,抑制晶粒增长,使光吸收带边发生红移。     

可见光活性的Ru掺杂TiO2光催化剂的制备及光解水制氢性能研究

采用溶胶—凝胶法制备了系列Ru掺杂TiO2光催化剂,并利用XRD和UV-Vis漫反射光谱对样品进行了表征。结果表明:Ru掺杂阻止了TiO2纳米粒子由锐钛矿向金红石相的转变,提高了TiO2对可见光的吸收强度。Ru掺杂的最佳浓度为0.014%,在可见光的照射下,Ru(0.014%)/TiO2对光解水制氢有较高的活性。     

低量Y3+掺杂对TiO2光催化活性的影响

利用溶胶-凝胶法在煅烧温度600 ℃制备了不同Y3 掺杂量的纳米TiO2粉体,并用XRD技术对样品进行了表征.研究了Y3 掺杂量对样品相结构、晶粒尺寸和光催化降解亚甲基蓝的活性的影响,利用相结构与纳米TiO2光催化活性关系探讨了Y3 掺杂对纳米TiO2的光催化活性.结果表明,适量掺杂Y3 可以提高其光催化活性.当Y3 掺杂量为0.04%, 纳米TiO2粉体的光催化活性最佳,降解率为94.6%,其金红石相含量为9.8%,平均粒径为12 nm,Y3 掺杂强烈地抑制TiO2由锐钛矿相向金红石相的转变,减小晶粒尺寸这两方面均有利于提高光催化活性.     

Fe3+掺杂纳米TiO2的表征及其光催化性能的研究

[目的]提高TiO2的可见光响应和光催化活性.[方法]采用溶胶凝胶法制备掺铁纳米TiO2粉体,进而研究掺铁TiO2的光催化活性.[结果]450 ℃煅烧后掺铁TiO2出现了很明显的TiO2特征衍射峰,且峰形尖锐,结晶良好,均没有出现铁的掺杂新相.随着掺铁量的提高,TiO2的粒径逐渐减小,当掺杂量为0.4%时,TiO2的粒径最小,减少至纯TiO2的45%.掺铁抑制了锐钛矿向金红石矿的转变.随着焙烧温度的升高,TiO2的粒径逐渐增大.用溶胶-凝胶法制备的TiO2均为纳米级,基本成球形颗粒.纯TiO2粒子分布不是很均匀,团聚现象明显;掺铁TiO2颗粒分布均匀,没有明显的团聚现象;掺铁使TiO2在紫外灯和太阳光下的降解性能都有着不同程度的提高.[结论]溶胶-凝胶法制备的掺铁纳米TiO2细化了晶体晶粒,抑制了锐钛矿向金红石矿的转变.     

中间层热处理温度对VO_2/TiO_2复合薄膜热致相变性能的影响

通过溶胶凝胶法在云母表面制备了Ti O2中间层薄膜,再在中间层上制备了VO2薄膜。通过视频光学接触角测量仪检测Ti O2薄膜的亲水性,利用XRD、傅立叶红外光谱仪和紫外可见分光光度计对复合薄膜的结构及光学特性进行分析。试验表明,紫外光激发后的Ti O2薄膜具有良好的亲水性,能够实现V溶胶的均匀涂覆。Ti O2中间层经510~560℃退火后,复合薄膜沿(011)晶面择优取向生长,复合薄膜红外屏蔽效能高,相变温度及滞后温宽都较低。中间层经460℃退火后的复合薄膜沿(111)晶面取向生长,红外屏蔽效能达到92%以上。     

低量Gd^3＋／Fe^3＋共掺杂TiO2制备及催化活性

利用溶胶-凝胶法在煅烧温度540℃制备了纯的和不同Gd^3＋／^3＋共掺杂的TiO2纳米粉体,并用XRD技术对样品进行了表征。研究了Gd^3＋／Fe^3＋共杂量对样品相结构、晶粒尺寸和光催化降解亚甲基蓝的活性的影响,利用相结构与纳米TiO2光催化活性关系探讨了Gd^2＋／Fe^3＋共掺杂对纳米TiO2的光催化活性。结果表明,与纯TiO2相比,适量共掺杂Gd^3＋／Fe^3＋可以显著提高其光催化活性。当Gd^3＋／Fe^3＋共掺杂量为0．04％／0．04％,Ti02纳米粉体的光催化活性最佳,降解率为89．96％,其金红石相含量为32％,平均晶粒粒径为30nm,Gd^3＋／Fe^3＋共掺杂强烈地抑制TiO2由锐钛矿相向金红石相的转变,减小晶粒尺寸这两方面均有利于提高光催化活性。     

Grain Size and Wettability of TiO2/SiO2 Photocatalytic Composite Thin Films

The uniform transparent TiO2/SiO2 photocatalytic composite thin films are prepared by sol-gel method on the soda lime glass substrates, and characterized by UV-visible spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), BET surface area, FTIR spectroscopy and X-ray photoelectron spectroscopy (XPS). It was found that the addition of SiO2 to TiO2 thin films can suppress the grain growth of TiO2 crystal, increase the hydroxyl content on the surface of TiO2 films, lower the contact angle for water on TiO2 films and enhance the hydrophilic property of TiO2 films. The super-hydrophilic TiO2/SiO2 photocatalytic composite thin films with the contact angle of 0-° are obtained by the addition of 10%-20% SiO2 in mole fraction.     

Preparation of Ce4+, Sb3+-Codoped TiO2 Films in Electric Field Heating-Treatment

Titania is an important catalytic material for photo-catalytic applications, and the sol-gel process is one of the most appropriate technologies to prepare TiO2 thin films. In the present paper, the Ce4 , Sb3 -codoped TiO2 films were prepared by sol-gel method, which were heat-treated with an applied electric filed. The phase transformation behavior of Ce4 , Sb3 -codoped TiO2 film in the electric field heating-treatment was studied by XRD and AFM. It is found that the crystals were homogeneous and the average crystal size was about 60 nm. Studies of photo-catalytic degradation show that the photo-catalytic activity of Ce4 , Sb3 -codoped TiO2 films heated to 500 ℃ in an applied electric field was higher.     

La~(3+) -doped SrBi_2Ta_2O_9 thin films for FRAM synthesized by sol-gel method

This paper discusses the possibility of synthesis of SBTL sol-gel films for use as active layers for non-volatile memory(FRAM). La-doped SrBi2Ta2O9 thin films were synthesized by sol-gel method on Pt/TiO2/BPSG/SiO2/Si substrates. The structural features of the surface(AFM), crystallization behavior(XRD) during the heating and ferroelectric properties of synthesized films were discussed. It was shown that an optimum surface structure and a high share of perovskite phase of SBTL-films were compared to SBT-films(Theating=800 oC). Achieved ferroelectric parameters suggested the possibility of using synthesized SBTL sol-gel films in non-volatile memory devices.     

叠层型Cu沉积TiO2复合薄膜的制备及光学性能

真空蒸镀法结合溶胶凝胶法成功地制备Cu-TiO23层复合结构薄膜.运用XRD,SEM,UV-vis等手段进行结构表征和光吸收性能测试.通过模拟可见光下制备样品对亚甲基蓝溶液降解率的变化,评定其光催化活性.结果表明:该法制备的复合结构薄膜,在未热处理时真空蒸镀的金属层为单质Cu.在723 K热处理后,沉积的Cu被氧化主要以Cu2O的形式存在,而TiO2为单一的锐钛矿晶型.823K保温2.0 h热处理后Cu2O进一步被氧化为CuO,同时出现了少量金红石型TiO2.由于Cu2O与CuO均为窄带隙的半导体,在可见光照射下会发生电子由价带向导带的跃迁,因此复合薄膜表现出明显的可见光吸收性能.降解实验的结果则表明:不同温度热处理后的复合薄膜均表现出较高的光催化活性,特别是723K热处理后的复合薄膜样品可见光催化活性最好,在可见光照射5.0 h后对亚甲基蓝溶液降解率接近100%.分析其原因认为,P型的Cu2O和CuO与n型TiO2半导体接触后,在其界面形成了纳米异质结的结合,其p-n结的内建电场抑制了光生载流予的再复合,提高了量子产率,因此使复合薄膜表现出较高的光催化性能.     

金属离子掺杂对离子液辅助制备纳米TiO_2性能的影响

以过渡金属(Cr、Fe、Ni和Zn)掺杂为手段,以溶胶凝胶为制备方法,以离子液2—羟基咪唑甲酸盐为微观结构调控试剂,制备了TiO_2纳米粒子。将样品备好后,在500℃的条件下进行煅烧处理,用BET、XRD、DRS等手段进行结构表征,以酸性蓝92为模拟污染物对其光催化性能进行测定。研究结果表明,经过渡金属掺杂后的TiO_2纳米颗粒比纯TiO_2具有更高的比表面积和更小的粒径尺寸。过渡金属的掺杂使TiO_2的吸收光谱向可见光的方向移动。在紫外灯照射下,水溶液中酸性蓝92的光降解结果为:过渡金属离子的存在使TiO_2纳米颗粒的光催化活性得到了明显增强。     

纳米TiO2薄膜的制备及自清洁性能研究

通过溶胶一凝胶法在普通钠钙玻璃表面制备均匀透明的纳米TiO2自清洁薄膜。探讨了薄膜制备的工艺条件，并利用X射线衍射（XRD）、紫外分光光度计对薄膜的晶型、晶粒大小和透光率进行了表征，研究了在紫外光照射下薄膜的光催化性能及亲水性能。结果表明，制得的TiO2薄膜具有较强的自清洁性能。     

Effects of Mineral Tourmaline Particles on Photocatalytic Activities of RE/TiO2 Composite Thin Films

The composite TiO2 films containing the mineral tourmaline particles and rare earth elements (T/RE/TiO2 )were prepared by a sol-gel method using Ti( OC4H9 )4 as raw material. The microstructure and forming mechanism of T/RE/TiO2 films were studied by scanning electron microscope (SEM). Effects of tourmaline on the photocatalytic activities of RE/TiO2 were determined by photocatalytic degradation of formaldehyde. The results show that the photocatalytic degradation ratio of formaldehyde increases by 44.2% with the composite films of Ce/TiO2 containing 0.04%tourmaline, more than that with the thin films of Ce/TiO2 under UV irradiation.     

Fe^3＋／Ce^3＋掺杂纳米TiO2的制备及光催化性能研究

采用溶胶-凝胶法制备了不同粒径的纯纳米TiO2和掺杂Fe^3＋和Ce^3＋的纳米TiO2。样品的X射线衍射（XRD）和透射电镜（TEM）表征说明：在相同的制备条件下，掺杂可以减小粒子粒径，掺Fe^3＋和Ce^3＋可以抑制晶相转变。光催化降解NO2的结果表明，在相同的制备方法和掺杂量的条件下合成的光催化剂对亚硝酸盐的降解率由高到低的顺序为：掺铁TiO2〉掺铈TiO2〉TiO2。     

Crystallization Behavior of Anatase Films in Applied Electric Field Heating Process

In this research the TiO2 thin films were prepared by sol-gel dip coating. The crystallization of the films in the applied electric field heating process was thoroughly studied by many technique, differential thermal analysis (DTA), Raman spectroscopy and atomic force microscope (AFM). Furthermore the phase formation, microstructure and photo-catalytic activity of TiO2 film were studied under the condition of an electric field heating-treatment. It is found that the existence of applied electric field promotes the phase transformation from anatase to rutile. Studies on photo-catalytic degradation show that the photo-catalytic activity of TiO2 thin films in an applied electric field is higher.     

镧、银离子掺杂对TiO_2光催化活性的影响

以钛酸四丁酯为原料,采用溶胶-凝胶法制备了纯的TiO2纳米粒子和掺杂镧、银离子并且浓度分别为2%,5%的TiO2纳米粒子。利用XRD和UV-VIS对其进行表征,且在日光条件下,以甲基橙的光催化降解为模型反应,考察了纯的TiO2纳米粒子及不同镧、银离子掺杂浓度下的TiO2纳米粒子光催化活性。结果表明,在掺杂镧、银离子后,TiO2的本征吸收光谱比未经掺杂的出现不同程度的红移,在氧化剂的协同作用下使得甲基橙的降解效率有明显提高。